2.1. Heterogeneity of Alternative Format Materials

The use of alternative format materials in library services began in Britain when John Troughton, who was visually impaired, was admitted to St. John’s University in 1656. Since 1857 when Liverpool Public Library started services for visually impaired people, which was the first public service for people with disabilities (Linley, 2000, p. 213), library communities have established policies for library services to support information accessibility for people with various types of disabilities. The American Library Associations (ALA) established a new standard for library services in 1978, which was the origin of the systematic public services for people with disabilities. In 2005, the Committee of Libraries Serving Disadvantaged Persons in the International Federation of Library Associations and Institutions (IFLA) suggested nine media formats that libraries should acquire to serve people with disabilities, including talking books, talking newspapers, talking periodicals, large print books, easy-to-read books, braille books, video/DVD books with subtitles and/or sign language, e-books, and tactile picture books (Irvall & Nielsen, 2005, p. 9). In addition to these formats, various alternative formats have been developed and included in library collections.

These formats have heterogeneous characteristics compared to general materials. The content in alternative formats is generally transformed from that of corresponding original materials in different formats (IMS Global Learning Consortium, 2002). Thus, both materials generally deliver identical or similar content and may share the same attributes, including author, subject, genre, and title of the work (Oliver, 2009, p. iii). During the transformation process, however, the original content is in most cases abridged or modified for suitability for each alternative format.

From a container perspective, many alternative format materials are currently published in complex formats in which physical and digital forms are combined, although traditional formats such as braille books are still broadly used. The adoption of these combined formats efficiently represents and delivers the content in a format optimized to each type of disability. Besides, the content of alternative format materials needs to be transformed and reproduced using several digital formats and may require specific equipment such as barcode readers and Text-To-Speech (TTS) devices that can implement the digitized content in appropriate forms.

Because of the advantages of digital formats, users and library communities tend to prefer materials in digital form to traditional printed materials. One of the reasons for this tendency is the time gap between printed and digital formats of alternative format materials. It is generally admitted that two years are needed to transform the content of general materials into printed alternative formats, which is destructively long (Carey, 2007, p. 769). In addition, the production of high-quality braille books is too costly and those books are difficult to digitize (Carey, 2007, p. 772).

For these reasons, most alternative format materials are currently published in digital or composite formats with heterogeneous bibliographic aspects. These unique characteristics may enhance information accessibility for people with disabilities, compared to traditional printed formats which rely on tactile sensation. In contrast, this resulted in difficulties in creating bibliographic records based on traditional descriptive rules and structures, such as the MARC format, because of their rigid and printed format-oriented structure.

2.2. Problems of Current Bibliographic Tools in Describing Alternative Format Materials

Hundreds of years of cataloging have shown that bibliographic description is an important tool with which to meet users’ information needs (Westlind, 2008, p. 428). Given this situation, it is imperative that library communities make efforts to provide detailed bibliographic descriptions for various alternative format materials to allow people with disabilities to efficiently and effectively access and utilize these materials. However, describing alternative format materials is not a simple task because of their heterogeneous characteristics and the continuous diversification of alternative formats. The following research identified the difficulties and limitations in describing materials in alternative formats.

Library communities in many countries generally follow some kind of national cataloging rules in describing alternative formats; these are mostly based on Anglo-American Cataloging Rules (AACR) (Westlind, 2008, p. 428). However, these rules were originally designed for general materials, especially printed book formats, not for alternative formats. Even worse, most of the rules for alternative formats focus on describing one specific type—braille books.

In regard to this, Atinmo (2007, p. 834) pointed out difficulties that visually impaired individuals have faced in retrieving alternative format materials. Because cataloging records do not fully reflect the unique bibliographic aspects of these materials, they may need intervention by staff, relatives, and friends in the process of book selection. Todaro (2005, p. 259) also mentioned that library catalogs link materials to users and those materials cannot be located without catalogs. However, not many libraries provide cataloging records for alternative format materials because of differently formatted catalogs.

In addition to this lack of alternative format-specific descriptive rules, most alternative formats in current forms are now produced in a digital format or a combined analog and digital format. The traditional methods of resource description based on the AACR2R and MARC format may not create specific identification of search elements as well as the relations of search elements to a descriptive resource because they are restricted to International Standard Bibliographic Description (ISBD) based description elements (Hider, 2012, p. 115).

With respect to cataloging rules, Lee et al. (2013) pointed out that the lack of alternative format-specific cataloging rules may hinder information accessibility for people with disabilities. To solve these problems, they proposed the revision, modification, and expansion of the Korean Cataloging Rules and Korean Machine Readable Cataloging (KORMARC) fields that comprehensively describe the various types of alternative format materials.

In spite of these continuous efforts, these problems and limitations are severe in the library community in South Korea. The National Library for the Disabled of South Korea constructed and has maintained the Direct Rapid Easy Accessible Material Service (DREAM) database since 2014. It is a national sharing system for alternative format materials that allows people with disabilities to search and use various alternative format materials. The main purpose of this database is to provide comprehensive information services for people with disabilities, by integrating and managing bibliographic records for alternative format materials created by public libraries and libraries for people with disabilities in South Korea (National Library for the Disabled, 2016). As of December 2017, the DREAM database has provided a total of 284,735 bibliographic records for various types of alternative format materials, including braille books, large-print books, easy-to-read books, electronic braille books, video/DVD books with subtitles and/or sign language, voice braille books, Digital Accessible Information System (DAISY), and Descriptive Video Service.

However, one of the problems of the DREAM database is that most of the bibliographic records were created in the KORMARC formation, which is one of the MARC formats for library collections in South Korea. Because of the fundamental limitations of the MARC format, the records contained in the database may describe only a few, but essential, bibliographic aspects of these materials, which may result in too-simple and incomplete resource description. Fig. 1 shows a bibliographic record in the DREAM database using the KORMARC format.

Fig. 1

KORMARC (Korean Machine Readable Cataloging) record for an alternative format material.

The material described in Fig. 1 is a DAISY format material published in 2000 for visually impaired individuals. Although this record is for an alternative format material, the description for the alternative format (fields 300, 500, 511, 518, and 521) and the corresponding original material (fields 200, 245, and 260) coexist in a single record. Fields 056, 653, and 700 describe the common aspects of both materials. Although these fields are essential in describing alternative format materials, this record seems to focus on the original material, with the addition of only a few aspects for the alternative format. This coexistence may make the record ambiguous, i.e., difficult to determine whether it is for the alternative format or the corresponding original material. In addition, it provides a very simple description for alternative format materials, and therefore it cannot provide sufficient access points appropriate to the unique characteristics of alternative format materials. Thus, there are many missing aspects that need to be described; for example, the publisher of the material. Even worse, this record describes the date of publication as 1996, which is the publication date of the corresponding original material, although the described material was published in 2000 in the current format.

One of the reasons for these problems is the lack of alternative format-specific fields in the MARC format. As a result, each field is used arbitrarily in the description of alternative format materials, depending on institutions or catalogers, and different values are assigned to the same field. In addition, it is difficult to expand or add new fields optimized to alternative formats because of the rigidity of the MARC structure. For these reasons, the construction of an eclectic and flexible bibliographic structure is inevitable to describe the unique aspects of alternative formats.

2.3. Approaches to Overcoming Limitations of Current Bibliographic Tools

As early as 2002, librarians were recognizing the limitations of the MARC format and the need for something to replace it (Sprochi, 2016, p. 130).

From the perspective of the digital environment, Coyle (2007, 2016) mentioned that entries in MARC format are determined by cataloging rules that may not be suitable in the current Web environment. In addition, the format is hardly suited to database storage and manipulation. Roine (2017) also insisted that the MARC format may not be suited for producing open and linked data in the changed information environment. Instead of MARC format, she suggested Bibliographic Framework (BIBFRAME), which is expressed in Resource Description Framework (RDF) format in order to clearly describe digital format resources and their reciprocal relations. Other researchers have also mentioned BIBFRAME to be fully compatible with Resource Description and Access (RDA) cataloging code, which is a new cataloging rule that can deal with the changed information environment (Baker et al., 2014; Kroeger, 2013; Sharma et al., 2018).

Different from these suggestions for adopting new cataloging rules, many research has proposed to adopt bibliographic metadata in describing resources. By mentioning the limitations of traditional bibliographic tools, Tennant (2002, p. 102) enumerated some of the inherent problems with the MARC format and suggested an XML-based system that would allow for flexibility and granularity of data. Westlind (2008, p. 426) also opined that metadata and bibliographic control are demanded because accessible alternative format materials are predominantly digital and increasingly dynamic. Consequently, he mentioned the dynamic characteristics of accessible materials and that the need for dynamic cataloging must be put into focus. In the same context, several researchers insisted that MARC records are replications of card cataloging and at no point can discrete data elements be adequately extracted from MARC for incorporation into the Web. Therefore, it might be necessary to adopt metadata in library communities in order to bring bibliographic records together in a structured way (Gardner, 2012; Thomale, 2010). Similar to these findings, Moledo (2018) insisted on the need for bibliographic metadata for alternative format materials as information about the functioning of library services and its accessibility by ensuring navigation throughout those materials.

In contrast, some research has pointed out that library operations contain high-quality structured metadata, but it is seldom integrated or linked with other Web resources (Knight, 2011; Tharani, 2015). In order to overcome these limitations in resource description, it might be necessary to share bibliographic metadata over the Web for libraries. Understanding these limitations, many research efforts have proposed approaches to apply metadata to describe alternative format materials.

The Croatian Library for the Blind, in co-operation with the Croatian Association of the Blind, started a project to create a digital archive, which is a digital collection for visually impaired people (Rightscom, 2007). The aim of this project is to collect the full text of various information sources for these people, as well as books and magazines, in the most accessible way by using modern communication technologies. The collected resources are described and incorporated using the Dublin Core element set.

Westlind (2008, p. 428) proposed an approach to collaborate Dublin Core and RDA. He applied this collaboration to the use of Dublin Core in DAISY, which is one of the representative alternative formats. However, the Dublin Core elements in DAISY have been criticized for not being useful for libraries with high requirements in terms of bibliographic information.

In 2004, the National Instructional Materials Accessibility Standard was developed in co-operation with the American Printing House for the Blind and the Center for Applied Special Technology. It is a file format for digital textbooks and instructional materials for students with visual and print disabilities. It is based on XML syntax and has achieved the highest degree of content access and flexibility in providing alternative format materials (National Center on Accessible Educational Materials, 2011). However, it is criticized as most of the current files are unusable because it rarely contains basic structural organization such as paragraph breaks, page breaks, and page numbers.

In 2018, Round Table on Information Access for People with Print Disabilities (2018) provided a guideline for producing Accessible eText, which is designed to provide a person with a print disability with equivalent access to the alternative version of an original material. This guideline insists that an accessible eText version of a print document should provide the same information as the original print document, including all meaningful elements of the print document, i.e., publishing information. It also focuses on providing structural markup for the eText version of materials by providing enhanced metadata information. They considered metadata for alternative format materials to facilitate the understanding, use, and management of the materials. However, this guideline does not provide the details of how to describe various types of alternative format materials and how to support the information accessibility of users.

Despite these limitations, library communities have attempted to adopt various metadata schemes to describe alternative format materials. This tendency may be inevitable because most of the current alternative formats adopt digital technologies, which are difficult to describe using traditional bibliographic tools. Metadata is sufficiently flexible to describe the unique and heterogeneous bibliographic aspects of alternative format materials to provide sufficient access points to these materials. In contrast, there is no standardized metadata convention that can be fully applied to the description of various types of alternative format materials.

3.1. Research Objectives

Alternative format materials are created not for general users, but for people with different types of disabilities who have many difficulties in accessing and utilizing information resources. In order to support the information accessibility of these people, it is necessary to have a structured metadata designed to manage alternative format materials. It should also be able to overcome the limitations of current bibliographic tools, support the integration, management, and processing of bibliographic records, and be suitable in the current Web environment.

For these reasons, this research attempts to construct a metadata framework optimized to alternative format materials, which can address the problems of traditional MARC structure and other existing metadata schemes when they describe those materials. The proposed metadata framework is not constructed from scratch, but is based on the existing bibliographic structures currently used in library communities, such as the MARC format and Metadata Object Description Schema (MODS).

3.2. Data Collection

The data set used to construct a metadata framework is from the analysis of existing bibliographic records for alternative format materials currently used in the library community. The records analyzed were mainly from the DREAM database. The records contained in the database may describe only a few, but essential bibliographic aspects of alternative format materials, which may result in incomplete resource description. Although the database has many limitations in describing alternative format materials, it paradoxically shows the essential and core bibliographic aspects of these materials, which should be included in the resource description. By analyzing the KORMARC fields commonly used in describing various types of alternative format materials, the core and essential bibliographic aspects of those materials can be identified and extracted. By taking advantage of its limitation, this research analyzes and identifies the KORMARC fields and assigned values to extract core aspects of alternative format materials. Table 1 shows the analyzed KORMARC fields that are currently used in describing alternative format materials.

As shown in Table 1, several fields are used in describing alternative format materials, although they are not alternative format-specific. These fields and assigned values can be divided into three categories: content related, physical forms related, and context related fields. Some of the fields, such as 056, 245, and 653, contain the same values as the corresponding original materials. Although these fields may not be sufficient to describe every aspect of the alternative format materials, they are considered to be bibliographic aspects indispensable to describing these materials. For these reasons, they were extracted as potential core elements that constitute a consistent and persistent bibliographic framework optimized to alternative format materials.

These extracted core elements function as container elements that encompass detailed and related elements as sub-elements. This is an efficient approach as it provides a hierarchical structure, which shows the element relationships and clearly represents the multi-aspect characteristics of these materials.

4.1. Intellectual Category

The elements in the Intellectual category describe the aspects related to the content of alternative format materials. The category also includes elements related to the participants involved in generating alternative format materials in the current forms. The elements proposed in this category are shown in Table 2.

In general, the content of a resource is created by a person or group of people and published by a person or an institution. In contrast, there are more agents involved in the generation or publication of alternative format materials than in the corresponding original materials. They may include readers, braille translators, and the agents who transform the original materials into alternative formats. Although they are not responsible for the original content of the materials, they play critical roles in transforming or generating alternative format materials. Therefore, it might be necessary to differentiate them from the author(s) of corresponding original material(s) and describe their roles. The element <agents> is proposed to incorporate the individuals and participants involved in the transformation and generation of alternative format materials. It has sub-elements that specify each participant, such as <brailleTranslator>, <reader>, and <signLanguageTranslator>. More elements can be added, if necessary, to describe other participants and their roles.

It might also be necessary to differentiate the publication of alternative format materials from that of corresponding original materials in a similar manner to the element <agents>. Although both materials may share identical or similar content, they are different items with different publishers and different user groups. The proposed element <altPublication> indicates the publication of alternative format materials. It has sub-elements such as <altPublisher>, <altDateIssed>, <altDateRecorded>, and <altPlace>, which specify the publication related information.

In some cases for materials for people with hearing disabilities, it might be necessary to indicate whether the materials provide additional languages, such as sign languages and subtitles, and what types of languages they provide. The element <altLanguage> is proposed with the sub-element <subtitle>, which indicates the languages of subtitles provided. For sign languages, ‘signLanguage’ can be applied as an attribute of the element <altLanguage> with a value of ‘yes’ to indicate that the material provides sign language. If there is no sign language provided, the attribute ‘signLanguage’ is not used.

4.2. Physical Category

Because many alternative format materials are currently published in extremely different formats from general printed materials by applying state-of-the-art information technologies, it might be necessary to indicate the containers of these materials and describe their physical characteristics. The Physical category is proposed to describe these heterogeneous physical characteristics of alternative format materials (Table 3).

Various formats with heterogeneous characteristics are currently applied in publishing or reproducing materials for people with disabilities. Indicating their formats is vital because it is directly connected to the utilization of the content of the materials. The element <altFormat> is proposed for this purpose and is expected to support the selection of alternative formats appropriate for each type of disability.

One of the difficulties related to the use of this element, however, is that there is no standardized way of indicating specific formats applied to these materials. Therefore, this research proposes a controlled vocabulary to consistently assign values to the element and precisely indicate the specific formats of these materials. The proposed list of alternative formats is basically based on the formats provided by IFLA. Some formats, such as human DAISY, are added to reflect newly emerging formats. Besides these physical formats, there are file formats applied to generate these materials, which also need to be differentiated from physical formats (Table 4). These different types of formats can be indicated by applying the sub-elements <physicalFormat> and <fileFormat>.

Some of these formats, especially the digital formats, may require specific equipment or software to implement their content. One of the representative examples is the barcode-inserted book, which requires equipment that can read barcodes and implement the content in an appropriate format. Because various equipment customized to each alternative format is currently used, the element <equipment> is proposed to precisely indicate the equipment required in the bibliographic descriptions. It can also be used to describe system or software requirements, for example, screen reader software and TTS software.

In the case of printed materials, such as braille or tactile picture books, the condition of wear-out affects the use and administration of these materials. The element <altCondition> is proposed to indicate the current condition of each printed material. It can also be applied to describe the specific condition of digital formats, such as the condition of the sound recording.

Another consideration is that many alternative format materials, especially in printed formats, consist of packages of multiple volumes with identical content to the corresponding original materials. The description of these materials needs to indicate this bibliographic composition. The element <volume> indicates the total number of volumes and the specific volume number of each divided item. This research suggests the formation of the assigned value as ‘specific volume number/total number of volume,’ for example, ‘3/4.’ This element can be applied to both printed and digital format materials, if necessary.

4.3. Contextual Category

The Contextual category describes the context of the use of alternative format materials. It includes elements that indicate target audiences, different versions of materials, and various relationships between alternative formats and other related materials (Table 5).

There are various types of disabilities for which alternative formats are designed or published. Therefore, it is necessary to indicate the main target audiences with specific types of disabilities for whom alternative format materials are published. The element <altAudience> and a controlled vocabulary for types of disabilities are proposed to indicate the target audiences and assign values in a consistent manner (Table 6). This element can have multiple values, if necessary.

The content of the original material is generally transformed or reproduced in various alternative formats. Thus, the content is interrelated and can be considered as different versions of identical or similar content. The element <altVersion> is used to identify these different versions and indicate the formats of available versions. Although the values of the element can be assigned in the form of plain text, the proposed controlled vocabulary for the element <altFormat> can also be applied.

Another consideration for the element <altVersion> is that the content of the original material is usually modified or abbreviated when transformed to or reproduced in alternative formats. It might be useful if the content status is indicated in the bibliographic description. Thus, this research proposes the attribute ‘contentStatus’ for the element <altVersion>. Possible values of the attribute are ‘full,’ ‘abbreviated,’ and ‘modified.’

The element <altIdentifier> is expected to indicate various identifiers assigned to the described materials, including URI and DOI. Although many alternative formats can be accessed on the Web or provided through Web databases, numerous printed formats remain on shelves. Therefore, this element can also be used to indicate shelf location, if necessary.

In addition to these proposed elements optimized to alternative format materials, it may be helpful if the description for the corresponding original material is provided, because it can support users in understanding the described alternative format materials and retrieving appropriate alternative format materials. Nevertheless, it should be separated from the description of alternative format materials to make it clear that the record is for alternative format materials.

The element <corresponding> is proposed to satisfy this purpose and can be used to indicate original materials. By using the independent element <corresponding>, the description of the original material can be separated from that of the alternative format material in one record. For the description of original materials, this research proposes the reuse of elements in MODS as sub-elements of <corresponding>. Because MODS contains sufficient bibliographic elements for various types of resources, the reuse of MODS elements can provide an efficient rich resource description. In addition, it can achieve interoperability with existing MODS records.

When using the element <corresponding>, however, not all aspects of corresponding materials need to be described, because the proposed metadata framework describes alternative format materials. The sub-elements of the element <corresponding> are used selectively only when it is necessary to provide a description for corresponding materials.

4.4. Shared Category

Most alternative format materials and corresponding original material share many common aspects, including author, title, subject, and genre. However, one of the problems with respect to this perspective is that the description for both materials coexists in a single record without any formal descriptive rule. To address this ambiguity, this research proposes the application of the ‘1:1 discipline’ (Urban, 2014), in which each resource description should be used for one resource only—an alternative format material.

Nevertheless, these common aspects need to be reflected in the bibliographic description because they are significant access points to alternative format materials. Thus, the proposed metadata framework should include not only alternative format-specific elements, but also elements to describe common aspects.

The Shared category is proposed to describe these common aspects of both materials. The elements in this category may indicate original content-related aspects, which may not be changed even if the original content is transformed or reproduced. Although the description for these aspects coexists in a record for an alternative format material, it is categorized into the additional category Shared and can be separated from the categories of core elements. The proposed elements in the Shared category are shown in Table 7.

The elements shown in Table 7 correspond to the MODS elements and KORMARC fields. Thus, the value of each element can be reused from the existing MODS elements or MARC fields, if necessary.